Novel artificial intelligence approach for automatic differentiation of fetal occiput anterior and non-occiput anterior positions during labor.

OBJECTIVES: To describe a newly developed machine-learning (ML) algorithm for the automatic recognition of fetal head position using transperineal ultrasound (TPU) during the second stage of labor and to describe its performance in differentiating between occiput anterior (OA) and non-OA positions. METHODS: This was a prospective cohort study including singleton term (> 37 weeks of gestation) pregnancies in the second stage of labor, with a non-anomalous fetus in cephalic presentation. Transabdominal ultrasound was performed to determine whether the fetal head position was OA or non-OA. For each case, one sonographic image of the fetal head was then acquired in an axial plane using TPU and saved for later offline analysis. Using the transabdominal sonographic diagnosis as the gold standard, a ML algorithm based on a pattern-recognition feed-forward neural network was trained on the TPU images to discriminate between OA and non-OA positions. In the training phase, the model tuned its parameters to approximate the training data (i.e. the training dataset) such that it would identify correctly the fetal head position, by exploiting geometric, morphological and intensity-based features of the images. In the testing phase, the algorithm was blinded to the occiput position as determined by transabdominal ultrasound. Using the test dataset, the ability of the ML algorithm to differentiate OA from non-OA fetal positions was assessed in terms of diagnostic accuracy. The F1 -score and precision-recall area under the curve (PR-AUC) were calculated to assess the algorithm's performance. Cohen's kappa (κ) was calculated to evaluate the agreement between the algorithm and the gold standard. RESULTS: Over a period of 24 months (February 2018 to January 2020), at 15 maternity hospitals affiliated to the International Study group on Labor ANd Delivery Sonography (ISLANDS), we enrolled into the study 1219 women in the second stage of labor. On the basis of transabdominal ultrasound, they were classified as OA (n = 801 (65.7%)) or non-OA (n = 418 (34.3%)). From the entire cohort (OA and non-OA), approximately 70% (n = 824) of the patients were assigned randomly to the training dataset and the rest (n = 395) were used as the test dataset. The ML-based algorithm correctly classified the fetal occiput position in 90.4% (357/395) of the test dataset, including 224/246 with OA (91.1%) and 133/149 with non-OA (89.3%) fetal head position. Evaluation of the algorithm's performance gave an F1 -score of 88.7% and a PR-AUC of 85.4%. The algorithm showed a balanced performance in the recognition of both OA and non-OA positions. The robustness of the algorithm was confirmed by high agreement with the gold standard (κ = 0.81; P < 0.0001). CONCLUSIONS: This newly developed ML-based algorithm for the automatic assessment of fetal head position using TPU can differentiate accurately, in most cases, between OA and non-OA positions in the second stage of labor. This algorithm has the potential to support not only obstetricians but also midwives and accoucheurs in the clinical use of TPU to determine fetal occiput position in the labor ward. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Radiofrequency echographic multispectrometry compared with dual X-ray absorptiometry for osteoporosis diagnosis on lumbar spine and femoral neck.

An innovative, non-ionizing technique to diagnose osteoporosis on lumbar spine and femoral neck was evaluated through a multicenter study involving 1914 women. The proposed method showed significant agreement with reference gold standard method and, therefore, a potential for early osteoporosis diagnoses and possibly improved patient management. INTRODUCTION: To assess precision (i.e., short term intra-operator precision) and diagnostic accuracy of an innovative non-ionizing technique, REMS (Radiofrequency Echographic Multi Spectrometry), in comparison with the clinical gold standard reference DXA (dual X-ray absorptiometry), through an observational multicenter clinical study. METHODS: In a multicenter cross-sectional observational study, a total of 1914 postmenopausal women (51-70 years) underwent spinal (n = 1553) and/or femoral (n = 1637) DXA, according to their medical prescription, and echographic scan of the same anatomical sites performed with the REMS approach. All the medical reports (DXA and REMS) were carefully checked to identify possible errors that could have caused inaccurate measurements: erroneous REMS reports were excluded, whereas erroneous DXA reports were re-analyzed where possible and otherwise excluded before assessing REMS accuracy. REMS precision was independently assessed. RESULTS: In the spinal group, quality assessment on medical reports produced the exclusion of 280 patients because of REMS errors and 78 patients because of DXA errors, whereas 296 DXA reports were re-analyzed and corrected. Analogously, in the femoral group there were 205 exclusions for REMS errors, 59 exclusions for DXA errors, and 217 re-analyzed DXA reports. In the resulting dataset (n = 1195 for spine, n = 1373 for femur) REMS outcome showed a good agreement with DXA: the average difference in bone mineral density (BMD, bias ± 2SD) was -0.004 ± 0.088 g/cm2 for spine and - 0.006 ± 0.076 g/cm2 for femur. Linear regression showed also that the two methods were well correlated: standard error of the estimate (SEE) was 5.3% for spine and 5.8% for femur. REMS precision, expressed as RMS-CV, was 0.38% for spine and 0.32% for femur. CONCLUSIONS: The REMS approach can be used for non-ionizing osteoporosis diagnosis directly on lumbar spine and femoral neck with a good level of accuracy and precision. However, a more rigorous operator training is needed to limit the erroneous acquisitions and to ensure the full clinical practicability.

Automatic ultrasound technique to measure angle of progression during labor.

OBJECTIVE: To evaluate the accuracy and reliability of an automatic ultrasound technique for assessment of the angle of progression (AoP) during labor. METHODS: Thirty-nine pregnant women in the second stage of labor, with fetus in cephalic presentation, underwent conventional labor management with additional translabial sonographic examination. AoP was measured in a total of 95 acquisition sessions, both automatically by an innovative algorithm and manually by an experienced sonographer, who was blinded to the algorithm outcome. The results obtained from the manual measurement were used as the reference against which the performance of the algorithm was assessed. In order to overcome the common difficulties encountered when visualizing by sonography the pubic symphysis, the AoP was measured by considering as the symphysis landmark its centroid rather than its distal point, thereby assuring high measurement reliability and reproducibility, while maintaining objectivity and accuracy in the evaluation of progression of labor. RESULTS: There was a strong and statistically significant correlation between AoP values measured by the algorithm and the reference values (r = 0.99, P < 0.001). The high accuracy provided by the automatic method was also highlighted by the corresponding high values of the coefficient of determination (r2 = 0.98) and the low residual errors (root mean square error = 2°27' (2.1%)). The global agreement between the two methods, assessed through Bland-Altman analysis, resulted in a negligible mean difference of 1°1' (limits of agreement, 4°29'). CONCLUSIONS: The proposed automatic algorithm is a reliable technique for measurement of the AoP. Its (relative) operator-independence has the potential to reduce human errors and speed up ultrasound acquisition time, which should facilitate management of women during labor. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Treatment of dynamic claw toe deformity flexor digitorum brevis tendon transfer to interosseous and lumbrical muscles: a literature survey.

The authors report the results of a literature survey of corrective surgical treatment based on FDL and FDB tendon transfer for dynamic claw toe deformities. The study revealed that FDL transfer was first described in 1967 by Malcolm A. Brahms in "Common Foot Problems", and FDB transfer was first mentioned in 1993 in the first edition of the treatise by G. Pisani "Trattato di Chirurgia del Piede". The paper also discusses the functional effect of FDB transfer, compared to FDL transfer.

Use of oxidized and regenerated cellulose in thyroid surgery: a prospective analysis as cause of postoperative hypocalcemia on 485 patients consecutively treated.

AIM: The intraoperative hemorrage determines an higher risk of parathyroid glands lesions, and laryngeal nerve injuries. We have examined if the use of oxidized and regenerated cellulose could be a cause of postoperative hypocalcemia because of the compression on the parathyroid glands or for tissue adhesions METHODS: From June 2009 to December 2010 we have examined 485 patients consecutively treated with total thyroidectomy. The cases examined were divided in two groups on the use of ionized cellulose (group A and B). 24 hours after surgical procedure, all patients were submitted to serum calcium evaluation. The data were analyzed with χ2 test and t-student test; P<0.05 was statistically significant. RESULTS: We have selected 372 cases out of 485 examined. We have registered after 10 hours from surgical procedure a case of hemorrhage with reintervention in group B (no use of cellulose). The cost of ionized cellulose is € 46; we have used this device in 212 cases on 372 patients undergone to total thyroidectomy, with a cost of € 9 752. The mean value of the serum calcium was statistically different between pre- and postoperative evaluation in all cases (P<0.0001) divided both on gender and on the use of hemostatic devices. CONCLUSION: In our experience, there isn't a statistically significant difference on incidence of postoperative hypocalcemia, related to use of ionized and regenerated cellulose on mean surgical time in all patients either treated with traditional surgery or with video-assisted procedure.

Emerging and re-emerging infectious disease in otorhinolaryngology.

SUMMARY: Emerging and re-emerging infectious disease in otorhinolaryngology (ENT) are an area of growing epidemiological and clinical interest. The aim of this section is to comprehensively report on the epidemiology of key infectious disease in otorhinolaryngology, reporting on their burden at the national and international level, expanding of the need of promoting and implementing preventive interventions, and the rationale of applying evidence-based, effective and cost- effective diagnostic, curative and preventive approaches. In particular, we focus on i) ENT viral infections (HIV, Epstein-Barr virus, Human Papilloma virus), retrieving the available evidence on their oncogenic potential; ii) typical and atypical mycobacteria infections; iii) non-specific granulomatous lymphadenopathy; iv) emerging paediatric ENT infectious diseases and the prevention of their complications; v) the growing burden of antimicrobial resistance in ENT and the strategies for its control in different clinical settings. We conclude by outlining knowledge gaps and action needed in ENT infectious diseases research and clinical practice and we make references to economic analysis in the field of ENT infectious diseases prevention and care.

Serum sex hormone levels after menopause and subsequent breast cancer.

BACKGROUND: High levels of androgens and estrogens have been reported to be associated with breast cancer. However, the multiplicity of factors that influence hormone levels and methodologic issues complicate the study of the relationship between steroid sex hormones and breast cancer. PURPOSE: Using an improved study design, we assessed prospectively the relationship between the principal steroid sex hormones in serum and the subsequent occurrence of invasive breast cancer in postmenopausal women. METHODS: Four thousand fifty-three healthy postmenopausal women aged 40-69 years, were enrolled from June 1987 through June 1992 in a prospective investigation of hormones and diet in the etiology of breast tumors (ORDET study) as part of a larger volunteer cohort of 10 788 premenopausal and postmenopausal women from Varese Province, northern Italy. At recruitment, blood samples were taken between 8:00 AM and 9:30 AM (after overnight fasting), and sera were preserved in -80 degree Celsius freezers. Women who had received hormone treatment in the 3 months prior to enrollment, who had bilateral ovariectomy, or who had a history of cancer or liver disease were not recruited. Twenty-five women in the final eligible cohort of postmenopausal women developed histologically confirmed, invasive breast cancer during the first 3.5 years of follow-up for the cohort (13 537 women-years). For each case subject, four control subjects were randomly chosen after matching for factors possibly affecting hormone preservation in serum. One case subject and eight control subjects were excluded because premenopausal hormonal patterns were found; thus, after also excluding the four control subjects matched to the ineligible case subject, we included 24 case and 88 control subjects. In the spring of 1994, stored sera of case and control subjects were assayed in a blinded manner for dehydroepiandrosterone sulfate and estradiol (E2) by in-house radioimmunoassay and for total and free testosterone and sex hormone-binding globulin by commercially available nonextraction iodination kits. Mean differences in risk factors were tested by analysis of variance for paired data. Relative risks (RRs) were estimated by conditional logistic regression analysis. All P values resulted from two-sided tests. RESULTS: Age-adjusted mean values of total testosterone, free testosterone, and E2 were significantly higher in case subjects than in control subjects: total testosterone, 0.34 ng/mL versus 0.25 ng/mL (P<.001); free testosterone, 1.07 pg/ml versus 0.77 pg/mL (P= .006); and E2, 25 pg/mL versus 22 pg/mL (P= .027). Age-adjusted RRs for breast cancer in increasing tertiles were as follows: for total testosterone, 1.0, 4.8, and 7.0 (P for trend =.026); for free testosterone, 1.0, 1.8, and 5.7 (P for trend=.005); and for total E2, 1.0, 7.1, and 5.5 (P for trend= .128). CONCLUSIONS AND IMPLICATIONS: This prospective study provides further evidence in support of the already established association between elevated estrogen levels and breast cancer. Even more importantly, it provides new evidence that high serum testosterone levels precede breast cancer occurrence.

Radiation dose and leukemia risk in patients treated for cancer of the cervix.

To quantify the risk of radiation-induced leukemia and provide further information on the nature of the relationship between dose and response, a case-control study was undertaken in a cohort of over 150,000 women with invasive cancer of the uterine cervix. The cases either were reported to one of 17 population-based cancer registries or were treated in any of 16 oncologic clinics in Canada, Europe, and the United States. Four controls were individually matched to each of 195 cases of leukemia on the basis of age and calendar year when diagnosed with cervical cancer and survival time. Leukemia diagnoses were verified by one hematologist. Radiation dose to active bone marrow was estimated by medical physicists on the basis of the original radiotherapy records of study subjects. The risk of chronic lymphocytic leukemia, one of the few malignancies without evidence for an association with ionizing radiation, was not increased [relative risk (RR) = 1.03; n = 52]. However, for all other forms of leukemia taken together (n = 143), a twofold risk was evident (RR = 2.0; 90% confidence interval = 1.0-4.2). Risk increased with increasing radiation dose until average doses of about 400 rad (4 Gy) were reached and then decreased at higher doses. This pattern is consistent with experimental data for which the down-turn in risk at high doses has been interpreted as due to killing of potentially leukemic cells. The dose-response information was modeled with various RR functions, accounting for the nonhomogeneous distribution of radiation dose during radiotherapy. The local radiation doses to each of 14 bone marrow compartments for each patient were incorporated in the models, and the corresponding risks were summed. A good fit to the observed data was obtained with a linear-exponential function, which included a positive linear induction term and a negative exponential term. The estimate of the excess RR per rad was 0.9%, and the estimated RR at 100 rad (1 Gy) was 1.7. The model proposed in this study of risk proportional to mass exposed and of risk to an individual given by the sum of incremental risks to anatomic sites appears to be applicable to a wide range of dose distributions. Furthermore, the pattern of leukemia incidence associated with different levels of radiation dose is consistent with a model postulating increasing risk with increasing exposure, modified at high doses by increased frequency of cell death, which reduces risk.

Androgens and breast cancer in premenopausal women.

We investigated the role of androgens in premenopausal breast cancer by comparing serum testosterone, dihydrotestosterone, androstenedione, dehydroepiandrosterone sulfate, progesterone, sex-hormone-binding globulin-binding capacity, and urinary testosterone and androstanediol in 63 women with breast adenocarcinoma and 70 healthy controls of similar age. With variables dichotomized at the 75th percentile, the age-adjusted relative risk was 3.4 (95% confidence interval, 1.6-7.3) for high versus low levels of serum testosterone, 2.1 (0.9-4.8) for urinary testosterone, and 2.5 (1.1-5.9) for serum dihydrotestosterone. We observed no differences in other hormones. The strength of the associations changed markedly with increasing time to the onset of the next menses. The risk for testosterone and dihydrotestosterone, which was negligible in women with onset within 5 days of sampling, increased progressively to nearly 10-fold higher than in unstratified data in women with onset 10 days or more after sampling. This study provides arguments in favor of a role for increased androgenic activity in premenopausal breast cancer. It also suggests that unknown factors related to cycle length may be important in modulating the strength of the association with testosterone. The results are discussed also in reference to possible biases and inadequacies in study design.

Serum and urinary androgens and risk of breast cancer in postmenopausal women.

Serum levels of testosterone, dihydrotestosterone, androstenedione, dehydroepiandrosterone sulfate, and sex hormone-binding globulin and urinary levels of testosterone and androstanediol were compared in 75 women with breast carcinoma and 150 age-matched healthy controls. Odds ratios for quartiles of hormones, adjusted for known potential confounders, were computed using conditional logistic regression. Risk of breast cancer was positively associated with levels of all androgens in serum and urine but appeared stronger for testosterone (for trend, P = 0.03) and dehydroepiandrosterone sulfate (for trend, P = 0.06) in serum and for testosterone (for trend, P = 0.001) and androstanediol (for trend, P = 0.04) in urine. The adjusted odd ratios for high versus low quartiles were 2.7 (95% confidence interval, 1.1-6.5) for serum testosterone, 2.8 (1.1-7.4) for dehydroepiandrosterone sulfate, 4.7 (1.8-12.1) for urinary testosterone, and 3.4 (1.4-8.7) for urinary androstanediol. These observations suggest that endogenous androgenic hormones may play an important role in the epidemiology of postmenopausal breast cancer in women.

A prospective study of diet, lifestyle, and genetic factors and the risk of cancer in Khon Kaen Province, northeast Thailand: description of the cohort.

Cohort studies are the preferred design in observational epidemiology, but few involving the general population have been performed in Asia, and most concern affluent urban populations. The Khon Kaen study has recruited about 25,000 subjects, aged mainly 35-64, from villages in the relatively underdeveloped north-east of Thailand. All subjects underwent simple physical examination, completed an interviewer-administered questionnaire (including sections on lifestyle, habits, and diet) and donated specimens of blood, which were processed and stored in a biological bank at -20 degrees C. Female subjects (about 16,500) were offered screening by Pap smear, and specimens of cells from the cervix were stored at -20 degrees C. This paper describes the methodology of the study, and the characteristics of the participants. Almost all subjects are peasant farmers, with low annual income and body mass, although 14.6% of women had a BMI in the obese range (>30 kg/m(2)). Smoking was common among men (78% regular smokers, most of whom used home-produced cigarettes), but rare among women. Fertility levels were relatively high, with a more than half the women having four or more live births. 23.4% of subjects were infected with the liver fluke Opisthorchis viverrini, known to be highly endemic in this region. Follow-up of the cohort is by record-linkage to the provincial cancer registry. By 2003, 762 cancer cases had occurred, the most common being cancers of the liver (363 cases) and cervix uteri (44 cases). The antecedents of these cancers are being investigated using a nested case-control approach. The cohort will yield increasing numbers of cancers for study in the next decade, giving important information on the relative importance of dietary and lifestyle factors in a rural population, undergoing gradual transition to a more westernised lifestyle.

Possibilities, limitations, and technique for the study of regional myocardial perfusion in man by Xenon-133.

The theoretical possibilities and the practical limitations of the Xenon-133 (133Xe) method for the study of regional myocardial perfusion in man are discussed. The techniques for data acqusition and processing developed over the past 5 years are described in detail. Illustrative examples of experimental findings are reported. The practical interpretation of the data, at the light of the influence of injection site, initial tracer distribution, constancy of counting geometry, spatial resolution, and Xenon retention in fat, is presented.

Conversations with a chimpanzee in a computer-controlled environment.

The linguistic-type skills of a young chimpanzee (Pan) acquired in a computer-controlled language-training situation are reviewed. Those skills include facile acquisition of vocabulary, object naming, color naming, appropriate use of "yes" and "no" in response to certain questions, and conversation. In conversations the subject has formulated novel sentences and without special training has asked that objects be named, whereupon requests were made that they be given to her. These findings are interpreted in terms of how enriched environments can serve to bring forth novel communication skills in the chimpanzee, which is otherwise alinguistic; how the challenge of the environment can serve to limit manifest intelligence; and how a cognitive, rather than the traditional stimulus-response, framework is required for understanding the communication skills and psychological processes of the chimpanzee.

Erratum: Estimates of the worldwide mortality from 25 cancers in 1990. Int. J. Cancer, 83, 18-29 (1999).

Pisani, P., Parkin, D.M., Bray, F. and Ferlay, J. Estimates of the worldwide mortality from 25 cancers in 1990. Int. J. Cancer, 83, 18-29 (1999). Due to a printer's error, incorrect table headings were entered in Tables II-IV after the proofs of the article had been approved by the author. The correct tables are reprinted on the following pages. The publisher regrets this error.

Environmental risk factors for nasopharyngeal carcinoma: a case-control study in northeastern Thailand.

A case-control study of nasopharyngeal carcinoma was conducted in northeast Thailand, a region which shows an intermediate risk for this neoplasm. The study was conducted to investigate the importance of environmental exposures, particularly salted fish consumption, cigarette smoking, alcohol drinking, and occupational exposure to smoke or dust, as risk factors for the disease. Data from 120 nasopharyngeal cancer cases and the same number of hospital-matched controls indicated that consumption of sea-salted fish at least once a week was a significant risk factor (odds ratio, 2.5; 95% confidence interval, 1.2-5.2). Agricultural workers were also at significantly higher risk (odds ratio, 2.8; 95% confidence interval, 1.3-6.2), and working in agriculture or as a woodcutter was associated with an even higher risk (odds ratio, 8.0; 95% confidence interval, 2.3-28.2). There was no association between nasopharyngeal carcinoma and alcohol drinking or cigarette smoking.

Cancer and infection: estimates of the attributable fraction in 1990.

Various estimates of the proportion of all cancers attributable to infections have been proposed but none have been numerically justified. We have reviewed the evidence for "causality" with respect to infectious agents linked with cancer and estimated the fraction of all cancer cases concerned that are attributable to it. The etiological fraction was applied to the estimated annual incidence of cancer at each specific site in 1990, and the number of attributable cases was obtained. We estimate that 15.6% (1,450,000 cases) of the worldwide incidence of cancer in 1990 can be attributed to infection with either the hepatitis B and C viruses, the human papillomaviruses, EBV, human T-cell lymphotrophic virus I, HIV, the bacterium Helicobacter pylori, schistosomes, or liver flukes. There would be 21% fewer cases of cancer in developing countries (1,000,000 fewer cases per year) and 9% fewer cases in developed countries (375,000 fewer cases per year) if these infectious diseases were prevented. The attributable fraction at the specific sites varies from 89% of cervix cancers attributable to the papillomaviruses to 1% of all leukemias attributable to human T-cell lymphotrophic virus I.

Validity for epidemiological studies of long-term cryoconservation of steroid and protein hormones in serum and plasma.

Prospective studies based on the storage of biological samples at low temperature have opened new perspectives in etiological research on cancer. In planning these studies a crucial question is to evaluate whether the long-term preservation of samples is able to affect the categorization of the subjects involved. In the frame of the ORDET project, a prospective study of hormones and diet in the etiology of breast cancer provided with a -80 degrees C biological bank, we have evaluated the stability of estradiol, free and total testosterone, and prolactin in serum and plasma samples over 3 years of cryoconservation. Study results showed that the subjects maintained almost the same rank by hormonal concentration throughout the 3-year period for all hormones. Looking at the stability over time, estradiol, prolactin, and total testosterone had fairly good performance for both serum and plasma. Serum-free testosterone increased in time up to 30%, whereas progesterone decreased by about 40% of the initial concentration. However, the reliability of the individual categorization by hormonal level suggests the validity of low temperature storage for epidemiological purposes, at least for hormonal parameters.

Repeated serum and urinary androgen measurements in premenopausal and postmenopausal women.

Intra-individual variability for serum and urinary hormones has been inadequately considered in previous studies. Therefore, in the planning phase of a prospective study of Hormones and Diet in the Etiology of Breast Cancer (ORDET study), androgen levels have been examined at two different times in 56 women (26 in premenopause and 30 in postmenopause). Hormonal measurements in serum showed a good level of agreement for both premenopause (pre) and postmenopause (post): androstenedione pre r = 0.70 (p less than 0.0001), post r = 0.77 (p less than 0.0001); testosterone pre r = 0.73 (p less than 0.0001), post log values r = 0.74 (p less than 0.0001). Dihydrotestosterone showed a good level for premenopause only: log values pre r = 0.82 (p less than 0.0001), post r = 0.41 (p less than 0.05). Agreement levels in urine were inferior to those of serum: testosterone pre r = 0.53 (p less than 0.05), post r = 0.41 (p less than 0.05); androstanediol log values r = 0.46 (p less than 0.001), post log values r = 0.57 (p less than 0.05). Correlation between the two measurements improves considering age, parity, time of blood collection and, for urine, the interval of sample collections.

Retrospective assessment of exposure by experts: the example of formaldehyde, solvents and mineral oils among textile and metal workers.

The validity of retrospective assessment of occupational exposure greatly depends on the amount of detail in the available information, on the knowledge of the specific industrial process by the experts, and on the criteria adopted to define relevant exposure. These criteria are difficult to standardize and are rarely made explicit in published reports, which makes it difficult to interpret inconsistencies among different studies. In two ongoing case-control studies on kidney cancer and, respectively, malignant lymphomas, a detailed occupational history was obtained and supplemented by 19 additional questionnaires, specifically addressing industrial activities where the knowledge of job title alone would have been insufficient for reliable exposure assessment. One further questionnaire was used to collect details of task and environment for all the other activities. These data are used to establish probability, intensity and frequency of exposure to 30 substances known or suspected to be carcinogenic from previous studies. There are two basic steps in the exposure assessment procedure: firstly, general rules are defined for each job within each activity covered by specific questionnaires; secondly the judgement is modulated according to the detailed tasks, working conditions and environment. To illustrate the process and to facilitate comparison with other studies, examples are given for a few common exposures in the textile and metal industries--the two most frequent economic activities in the study area--namely exposure to mineral oils, formaldehyde, aromatic solvents, chlorinated solvents and other organic solvents.

Sources of discrepancies between a job exposure matrix and a case by case expert assessment for occupational exposure to formaldehyde and wood-dust.

Two methods used for retrospective evaluation of occupational exposures, a case by case assessment by expert and the application of a job exposure matrix (JEM), are compared using occupational histories collected for a case-control study on sinonasal cancer. The objective was to identify the main sources of discrepancies and to contribute to an optimal use of a JEM for population-based case-control studies. Comparisons were based on job periods, and were performed separately for two substances: formaldehyde and wood-dust. Job periods were classified according to the category of exposure assigned by the matrix, and to the probability and level of exposure assessed by the study expert. The sources of discrepancies were examined for job periods probably or definitely exposed according to the JEM and unexposed for the expert, or unexposed in the JEM and probably or definitely exposed to medium or high level for the expert. Such discrepancies were observed for 8% of the job periods for formaldehyde and 3% of the job periods for wood-dust. The agreement between the two approaches was better for wood-dust than for formaldehyde. The relative importance of different sources of discrepancies was not the same for formaldehyde and wood-dust. For formaldehyde a substantial part of the discrepancies was due to disagreements between the study expert and the matrix experts, which were mostly differences in threshold limits between 'not exposed' and 'definitely exposed at a low level'. Differences between experts' opinions did not explain the discordances observed for wood-dust. The presence of additional information in the questionnaire was an important source of discrepancy for the two substances.(ABSTRACT TRUNCATED AT 250 WORDS)